The proposal to tax billionaires’ wealth in California is quickly evolving into one of the biggest economic controversies in the United States. While proponents of the policy believe it could generate significant revenue for public services, opponents fear it could cause a loss of millionaires and wealthy people in California.

Silicon Valley’s growth over recent decades has made California rich — and one of the most unequal places in America.

A potential billionaire exodus would take decades to turn the proposed 5% wealth tax into a net loss for the state, NBER paper finds.

The proposal to tax billionaires’ wealth in California is quickly evolving into one of the biggest economic controversies in the United States. While proponents of the policy…